What is the value of the num_colors variable? var colors = ["red","blue","orange","yellow","gr een","brown","purple"]; num_colors = colors. length

The fourth generation of computers emerged between 1970s and 1980s. which technological advancement brought about this generation of computers? which computer architecture was used most in this generation?

In a word processing program, such as microsoft word, which feature to you choose the desired picture enhancement?

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?